requireNamespace etiquette

requireNamespace etiquette

I'm trying to resolve a problem of Namespaces and probably have misunderstood something basic.
In my quantreg package the function crq() has as its first argument a formula that typically contains
something like this: Surv(y, ...) ~ foo, where Surv is a function from the survival package which
quantreg suggests. When this syntax is encountered in ordinary usage Surv is resolved, I believe,
because near the beginning of the crq code there is the locution: